Gemini Observatory records volcanic gravity waves over Hawai’i, U.S.

Hours after the massive eruption at Hunga Tonga-Hunga Ha'apai¹ volcano on January 15, 2022, cameras at the Gemini Observatory on Mauna Kea, Hawai'i, U.S. recorded red waves rippling over Hawai'i.

"These are gravity waves, a type of atmospheric disturbance excited by intense thunderstorms and volcanic eruptions," Dr. Tony Phillips of the SpacveWeather said.²

While many gravity waves scud through the low atmosphere, the ripples caught by Gemini's Cloudcam, were in the mesosphere 85 km (53 miles) high.

These waves, seen in the video below, are red because of airglow, an aurora-like phenomenon caused by chemical reactions in the upper atmosphere.

Airglow is usually too faint to see, but gravity waves from the volcano boosted the reaction rates. Red is a sign of OH — a neutral molecule that exists in a thin layer 85 km high and can produce a pure red light, Phillips said.

Gravity waves over Hawai'i were spotted by photographer Steve Cullen.

"I had a hunch that Gemini Cloudcams might detect gravity waves produced by the eruption of Hunga Tonga-Hunga Ha'apai. So, I just took a look and there they were!"

"The volcanic eruption happened at 04:15 UTC, and the gravity waves passed Hawaii 4.5 hours later," notes Cullen. "This corresponds to a speed of ~1 100 km/h (683 mph)."

Reference:

¹ Massive eruption at Hunga Tonga-Hunga Ha'apai produces huge shockwave and tsunami, Tonga – The Watchers

² Volcanic Gravity Waves over Hawaii – SpaceWeather

Featured image credit: Gemini Observatory